OICC Press Iranian Journal of Catalysis 2345-4865 8 2 2024 02 03 Hydrothermally synthesized nanocrystalline Nb2O5 and its visible-light photocatalytic activity for the degradation of congo red and methylene blue EN Subhash Dharmraj Khairnar Nano-Chemistry Research Laboratory, G. T. Patil College, Nandurbar-425412 (M.S), India. 0000-0002-6732-366X Manohar Rajendra Patil Nano-Chemistry Research Laboratory, G. T. Patil College, Nandurbar-425412 (M.S), India. Vinod Shankar Shrivastava Nano-Chemistry Research Laboratory, G. T. Patil College, Nandurbar-425412 (M.S), India. Journal Article 2024 02 03 Nb2O5 nanoparticles were synthesized by the hydrothermal method. Structural, morphological and elemental analysis of synthesized Nb2O5 nanoparticles was carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy, respectively. The average crystal size calculations were performed on the basis of X-ray diffraction pattern and were about 12.44 nm. The synthesized Nb2O5 nanoparticles were explored for the photocatalytic degradation of congo red (CR) and methylene blue (MB) dyes in their aqueous solutions using a spectrophotometric method. For the Photocatalytic degradation of both the dyes, pH of dye solutions was varied in the range of 2 to 10. For the optimization, the maximum decolorization of 90 % and 87 % was observed for low initial dye concentration of 10 mg/L and pH values of CR and MB dyes were about 8 and 2, respectively. Besides, the effects of parameters such as the contact time and catalyst dose were studied systematically.